Strabismus and Ocular Motility Flashcards
What all does the superior rectus muscle do?
elevates (primary action), adducts and intorts
What all does the inferior rectus muscle do?
depresses, adducts and excyclotort
WHat does the inferior oblique do?
elevates and extorts
What is duction?
movement of one eye
What is version?
movement of both eyes (conjugate)
What is vergences?
disconjugate movement of eyes
What is strabismus?
misalignment of visual axes
What is phoria?
latent deviation that appears only when fusion is disrupted
sometimes deviated
What is tropia?
manifest deviation, beyond the range of fusional control
always deviated
What can you use the corneal light reflex for>
to determine if the eye is deviated in a particular direction based on where the light reflex shows up
How can you determine if someone has a tropia?
use cover-uncover test and if eye deviates with covering then you have a tropia
How can you tell if someone has phoria?
use the cross cover test. You do the cover uncover test and nothing happens but when you cover one eye and then cross horizontally to the other eye, the eye deviates which lets you know that the deviation is there only SOME of the time, thus it is a phoria.i.e when you break fusioN!
What is esotropia?
nasalward deviation of eye “crossed eye”
What is exotropia?
temporal deviation “wall eyed”
What is hypertropia?
vertical deviation, relative to higher eye
What is this:
angle of devation remains constant regardless of direction of gaze, range of motion of eyes is full, wihout limitations or restrictions.
When is this most commonly seen?
concomitant deviation
in childhood onset strabismus
What is this:
Angle of strabismus varies with gaze diraction; limitation of ocular movements. Patient may exhibit abnormal head posture to maintain binocularity.
Is this congenital or acquired?
incomitant deviation
may be congenital or acquired
How do you get comitant deviations?
abnormalities of binocularity, motion processing, poor fusional vergences
How do you et incomitant deviations?
developmental (Duanes, Browns), neurological (cranial nerve palsy, myasthenia), restrictive (trauma, thyroid disease)